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60x-x^{2}=0
Subtract x^{2} from both sides.
x\left(60-x\right)=0
Factor out x.
x=0 x=60
To find equation solutions, solve x=0 and 60-x=0.
60x-x^{2}=0
Subtract x^{2} from both sides.
-x^{2}+60x=0
All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. The quadratic formula gives two solutions, one when ± is addition and one when it is subtraction.
x=\frac{-60±\sqrt{60^{2}}}{2\left(-1\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, 60 for b, and 0 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-60±60}{2\left(-1\right)}
Take the square root of 60^{2}.
x=\frac{-60±60}{-2}
Multiply 2 times -1.
x=\frac{0}{-2}
Now solve the equation x=\frac{-60±60}{-2} when ± is plus. Add -60 to 60.
x=0
Divide 0 by -2.
x=-\frac{120}{-2}
Now solve the equation x=\frac{-60±60}{-2} when ± is minus. Subtract 60 from -60.
x=60
Divide -120 by -2.
x=0 x=60
The equation is now solved.
60x-x^{2}=0
Subtract x^{2} from both sides.
-x^{2}+60x=0
Quadratic equations such as this one can be solved by completing the square. In order to complete the square, the equation must first be in the form x^{2}+bx=c.
\frac{-x^{2}+60x}{-1}=\frac{0}{-1}
Divide both sides by -1.
x^{2}+\frac{60}{-1}x=\frac{0}{-1}
Dividing by -1 undoes the multiplication by -1.
x^{2}-60x=\frac{0}{-1}
Divide 60 by -1.
x^{2}-60x=0
Divide 0 by -1.
x^{2}-60x+\left(-30\right)^{2}=\left(-30\right)^{2}
Divide -60, the coefficient of the x term, by 2 to get -30. Then add the square of -30 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-60x+900=900
Square -30.
\left(x-30\right)^{2}=900
Factor x^{2}-60x+900. In general, when x^{2}+bx+c is a perfect square, it can always be factored as \left(x+\frac{b}{2}\right)^{2}.
\sqrt{\left(x-30\right)^{2}}=\sqrt{900}
Take the square root of both sides of the equation.
x-30=30 x-30=-30
Simplify.
x=60 x=0
Add 30 to both sides of the equation.